Glossary
What is a power push over?
A loss-of-control event associated with unloading the rotor while thrust is applied. The mechanism is worth understanding. The handling is not something to learn from a web page, and this one does not try to teach it.
A loss-of-control event associated with unloading the rotor while thrust is applied, more likely on certain airframe geometries. It appears repeatedly in accident reports, which is why type-specific instruction matters. Treat any general description, including this one, as background rather than as training.
Also called PPO, bunt over
Read this first
This page explains, it does not train
What follows is the mechanism: what is happening to the aircraft and why. It contains no recovery technique and no control inputs, deliberately.
A power push over develops quickly and the window for doing anything about it is small. Reading a procedure here and believing you could execute it would leave you worse off than knowing only that the situation must be avoided. Avoidance is taught in an aircraft, on your type, by an instructor rated for it.
If you fly gyroplanes or intend to, this is a conversation to have with a qualified instructor before your next flight, not after. Our instructor directory and school directory list who teaches.
What "unloading the rotor" means
A gyroplane rotor is turned by air flowing up through the disc. Nothing drives it. That airflow exists because the disc is carrying the weight of the aircraft: the rotor is loaded, air is pushed through it, and the rotor keeps turning. The full explanation is in what is autorotation.
Unloading the rotor means reducing or removing that load. It happens whenever the aircraft is pushed toward a condition where the rotor is carrying less than the weight of the machine, which a pilot can produce with the stick.
Remove the load and you remove the airflow that keeps the rotor turning. The rotor slows. A slowing rotor carries less, which unloads it further. That is the part that makes this different from most other things that go wrong in an aircraft: it feeds itself.
Why thrust makes it worse
On most modern gyroplanes the engine and propeller sit behind and above the cabin, in the pusher configuration. That puts the line of thrust somewhere above the aircraft's centre of gravity.
Thrust acting above the centre of gravity tends to pitch the nose down. In normal flight the rotor is loaded and the airframe resists that: the aircraft is stable and the moment is balanced out. With the rotor unloaded, the thing doing the resisting is no longer doing it, and the pitching moment from the propeller is left acting on an aircraft that has lost the authority to counter it.
That is the combination in the name. Power, and a push over. Either alone is a manageable situation. Together, with the rotor unloaded, the aircraft can pitch forward faster than the rotor can recover, and a rotor that has slowed too far can strike the airframe.
How much a given design is exposed to this depends on where the thrustline sits relative to the centre of gravity, on the tail, and on other factors that are genuinely debated among people better qualified than this site. We are not going to tell you that one layout is safe.
What actually reduces the risk
Everything in this list is a decision made on the ground or a habit built in training. None of it is a technique to attempt in the air on the strength of having read it here.
- Type-specific instruction. Aeroplane hours do not prepare you for this, and neither do helicopter hours. The discipline of keeping a rotor loaded is particular to this aircraft.
- Training on the type you fly, not a similar one. Exposure varies by design, so the relevant handling is the handling of your machine.
- Currency. This is a skill that decays. A long gap is a reason to fly with an instructor before flying alone.
- Knowing your aircraft flight manual. The limits, the speeds and the procedures for your aircraft are in it. They are not on this site, because they differ by type and a figure carried out of context is worse than none.
- Asking your instructor directly about it. By name. A good one will welcome the question and will have a clear answer about how it is briefed and demonstrated on your type.
Notice what is not in that list: any description of what to do with the controls. That is not an oversight. It belongs to an instructor in an aircraft, and putting it here would invite somebody to rehearse it from memory at the moment they can least afford to.
Why this term is on a marketplace
Because somebody researching their first gyroplane deserves to meet this word here rather than later. It appears repeatedly in accident reports, and a buyer comparing aircraft should know it exists, know it is a training subject, and know to ask about it.
It is not a reason to avoid the aircraft. It is a reason to treat the training seriously and to buy from people who talk about it openly. A seller or a school that waves the question away has told you something useful.
